Weird noise coming from the dash or possible radio

[Gee]

Yes hello I have a 2005 LS and when I start up the engine every time there is a hissing or funny noise that I can hear wgen the radio is. Not on. Not sure what it is but it's annoying does anyone know what this hissing or weird noise is that I'm hearing ALSO how do u resolve this.

Thanx

 

[joegr]

Usually, a hissing noise from in the dash is the air conditioning thermal expansion valve. The hissing would indicate that the system is low on refrigerant and the expansion valve can't fully compensate for that. Do you get the noise if the climate control is completely off? (wait a minute of two after turning it off to listen for it)

Which radio do you have? The THX nav units do have weird tone noise that they make the first time the engine passes 2K RPM while driving. It's a known bug.

 

[Gee]

Yes I have the THX the noise definitely is herd while the system is off a.c. and radio I can here it clearly also when I look at the navigation I can see like lines almost like the tv back in the day going up and down as if it will cut off at some point.. the nav

 

[joegr]

Yep, there is even a TSB out about it. There is no solution to the noise/tone. It's some sort of interaction between the amplifier (in the trunk) or the wiring to it, and the ABS. It happens when the ABS runs a particular self test. My 06 does this, and has done it since the day it was new. It's actually slightly worse with the radio off than when it is on. I replaced the head unit (not because of the noise), but not the amp. I still have the noise.

 

[Gee]

O wow ok.... well thanx for the info.. I appreciate it